In a democratic society, freedom of speech and press are baste rights protected by constitution. Yet what kind of freedom of speech are indispensable and indispensable and what are the proper principles of limits on it are enduring issues in the history of constitutional theories and practices. While Meiklejohn based his defense of freedom of political speech on the doctrine of ”self-government”, John Rawls tried to do the same job from another way, namely, his theory of justice. This essay is meant to be an explication and analysis of his views and theory which ground his defense of freedom of political speech.